DE69637295T2 - DEVICE FOR ADAPTING SMALL-BAND LANGUAGE TRANSPORT OF A LOCAL ACCESS NETWORK FOR TRANSMISSION OVER A BROADBAND NETWORK WITH ASYNCHRONOUS TRANSFER MODE - Google Patents

Description

TECHNICAL BACKGROUND OF THE INVENTION

The The present invention relates generally to telecommunications systems and architectures, specifically, it relates to a device for adjusting the Narrowband voice traffic of a local access network to the transmission over a broadband network with asynchronous transfer mode to enable and provide means over the voice traffic be generated on a telephone in the narrowband network and on one User terminal in the broadband network and vice versa, even if different digital voice protocols are used.

BACKGROUND OF THE INVENTION

Existing Narrowband telecommunications networks are the primary means for transporting voice traffic between source and destination arrays The existing narrowband telecommunications networks are however, it may not be able to handle the increasing capacity of voice data as well as processing the pure data and video traffic. Another problem arises from the fact that these existing narrowband telecommunications networks Speech-dominated digital local exchanges, transit routes and private network switches include, because of the significant Invest in the hardware and service software of this digital Switch will be available for a long time. The providers of Network services want the functionality of their revenue-generating ones Preserving voice network systems, and yet with the growing capacity of voice, Data and video traffic can keep pace. The network service providers want Lower their operating and maintenance costs by having only one backbone network support that all Services supported - language, Data, pictures and video.

Furthermore uses the conventional backbone network on which local access networks are built a synchronous transfer mode signal format which takes the form of DS0 level signals which are multiplexed within DS1-level signals, which in turn are multiplexed within DS3 level signals or as VT1.5 signals in SONET (Synchronous Optical Network) STS-1 signals which in turn are within SONET higher level signals are multiplexed. Enable ATM formats (asynchronous transfer mode) however, the individual or group-wise multiplexing from DS0, DS1, DS3 and other service traffic types directly in chained payloads of high-speed lines and high capacity for the Transport and forwarding / switching. The benefits of bandwidth management asynchronous transfer mode with fast path recovery and more efficient bandwidth utilization awaken the desire to Format of asynchronous transfer mode as backbone for transmission of voice traffic. It is therefore desirable to use a backbone asynchronous transfer mode with existing narrowband telecommunications networks to implement to handle the growing capacity of voice, data and video traffic to be able to.

One ATM backbone network must deal with a number of new conditions can. One of these conditions is that impairments of the access network eliminated in the previously untreated voice traffic Need to become, before this voice traffic as ATM traffic streams in the Broadband network arrives. In such a case is a device required as a network resource for those deployed on the network Speech treatment is used.

The patent WO 94/11975 (against which the independent claims are delimited) describes a method for establishing telecommunication call paths in broadband communication networks in which pulse coded modulation signal streams are converted into asynchronous transfer mode cells for switching and transmission over a telecommunication network.

Out these explanations It becomes clear that a need has developed for a backbone network with asynchronous transfer mode, the problem of increasing capacity existing defuse local narrowband telecommunications networks. Furthermore there has been a need to adapt narrowband voice services for transmission along the broadband backbone network. In addition, a need has arisen for a new network element that allows for effective cross-network Processing provides and conversion between existing narrowband telecommunications networks and the backbone broadband network.

SUMMARY OF THE INVENTION

The Aspects of the present invention are described in the appended claims.

According to embodiments of the present invention, an apparatus is provided for adapting the narrowband voice data ver traffic (ie, traffic that includes services provided at 1544 Mbps or less) of a local access network for transmission over an asynchronous transfer mode broadband network, which device eliminates or reduces the disadvantages and problems of voice transmission over existing narrowband telecommunications networks.

According to the embodiment The present invention provides an apparatus for adapting the narrowband voice traffic of a local access network for transmission over Broadband network with asynchronous transfer mode, this device a network interface scarf includes device that operated so can that they have narrowband voice traffic from the local access network receive and narrowband voice traffic into the local access network can send. A transceiver circuit provides narrowband voice traffic Framing and timing functions that Speech processing circuit can eliminate echo effects and to improve the voice quality, and a Cell adapter circuitry converts the narrowband voice traffic in asynchronous transfer mode cells or asynchronous transfer mode cells around. A formatting circuit sends and receives synchronous optical network signals, which transport the asynchronous transfer mode cells in and out the broadband network with asynchronous transfer mode.

embodiments The present invention provides various technical advantages across from existing narrowband telecommunications networks. A technical Advantage is for example in the conversion of narrowband voice traffic in asynchronous broadband transfer mode cells. Another technical advantage lies in maintaining the functionality of existing narrowband telecommunications networks, while same time the advantages of the technology of asynchronous transfer mode be used. Another technical advantage is the provision a device that provides an interface between local narrowband access networks and a backbone broadband network with asynchronous transfer mode forms. Another technical advantage is the provision a device that adjusts various digital voice streams and thus allowing communication on calls from non-compliant network terminals. Another technical advantage lies in providing a Device that downloadable Software accepted by a network management center and thus the processing of voice traffic or voiceband traffic allows and which provides a processing system that performs such processing allows. This processing may include the following functions, however not limited to these: speech enhancement, speech protocol conversion, encryption Voice Compression / Decompression, SDLC / HDLC Compression (Synchronous Data link control / high-level data link control) for data traffic, in one or more DS0 signals between the narrowband access network and the backbone broadband network. Another technical Advantage is the provision of the ATM switching server function to carry out voice features, if needed, within the broadband network for traffic, which is fed into the network without proper treatment has been. The configuration of this device does not include any physical DS1 ports (T1 (E1), but constructs the DS1 lines from the incoming data streams new, handles the DS0 voice channels individually within the DS1 lines and converts the lines subsequently back in ATM cell streams which will be forwarded to the specified destination. Both Directions of the voice connection must be the same To be directed. Other technical advantages are for the Specialist from the attached Drawings, descriptions and claims readily apparent.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more comprehensive understanding The present invention and its advantages will be apparent here to the following description taken in conjunction with the accompanying drawings referenced, wherein like reference numerals refer to like parts and where:

1 Figure 10 is a block diagram of a backbone broadband network with asynchronous transfer mode and an interface to local narrowband access networks of a cross-connect network carrier;

2 FIG. 10 is a block diagram of an asynchronous transfer mode voice adaptation apparatus for use as an interface to and from the asynchronous transfer mode backbone network; FIG.

3 FIG. 12 is a block diagram of a ring structure for the backbone broadband network with asynchronous transfer mode; FIG.

4 shows a block diagram of an alternative embodiment for the speech adaptation device; and

5 shows different applications for the voice adaptation device within a telecommunications network.

DETAILED DESCRIPTION OF THE INVENTION

1 Figure 10 is a block diagram of part of a telecommunications network 10 , The telecommunications network 10 includes a local network carrier 12 and a cross-connection network carrier 14 , The local network carrier 12 and the cross-connection network carrier 14 Generate and send narrowband voice traffic in T1 / E1 signals to other area network carriers, other cross-link carriers, or local subscribers connected to the area network carrier 12 or the cross-connection network carrier 14 are connected. The telecommunications network 10 also includes a Backbone Broadband Network with Asynchronous Transfer Mode (ATM) 16 in contrast to the backbone network with synchronous transfer mode, as occurs in conventional telecommunications networks.

For transmitting narrowband voice traffic between the exchanges within the telecommunications network 10 For example, the T1 / E1 signals must be converted to an ATM cell format. The conversion of T1 / E1 signals into the ATM cell format is performed by a speech adaptation device 18 carried out. The speech adaptation device 18 performs the adaptation of the DS1 (T1 / E1) signals, which have a continuous bit rate and transport predominantly voice services, into synchronous optical network signal (SONET) data in ATM cell format.

The speech adaptation device 18 It also conditions all voice traffic for improved voice quality and cleans up voiceband echo effects on all voice traffic coming from carrier networks with access to the ATM backbone network 16 comes. The speech adaptation device 18 In addition, the T1 / E1 signals may actually compress less than the sum of the input / output service capacity over the ATM backbone network 16 is transmitted. A change of the field "virtual path identifier" in the asynchronous transfer mode cell format can be done by the speech adaptation device 18 to adapt the routing of the SONET signals, thus avoiding network errors and network bottlenecks.

2 Fig. 10 is a block diagram of a speech adaptation apparatus 18 , The speech adaptation device 18 includes a T1 / E1 network adapter 50 and a formatting unit 52 for synchronous optical networks (SONET). The T1 / E1 network adapter 50 converts T1 / E1 signals, which transport predominantly narrowband voice services, into and out of the asynchronous transfer mode cell format. The formatting unit 52 For synchronous optical networks, asynchronous transfer mode cells place cells from synchronous optical network signals for transmission into and out of the ATM backbone broadband network 16 ,

In the direction of transmission to the ATM backbone broadband network 16 The T1 / E1 network adapter is receiving 50 the speech adaptation device 18 Local T1 / E1 signals on a T1 / E1 interface 54 , The T1 / E1 interface 54 includes transducers for receiving T1 / E1 signals to a transceiver 56 to be provided. The transceiver 56 performs framing and timing functions with the T1 / E1 signals.

After the transceiver 56 has performed the framing and timing functions with the T1 / E1 signals, the narrowband voice traffic is passed to an echo canceler and a voice enhancement unit 58 Posted. The echo canceler and speech enhancement unit 58 perform two functions: The first function is to clean up voiceband echo effects in narrowband voice traffic originating from the local access networks. The second function is to condition the narrowband voice traffic for improved voice quality. All narrowband voice traffic destined for handoff to the ATM backbone broadband network is treated to eliminate the echo potential due to transmission delay delays.

The need to handle all narrowband voice traffic to eliminate potential echo problems results from the use of ring structures in the ATM backbone network 16 , 3 shows a ring structure 59 within the ATM backbone broadband network 16 , Under normal circumstances, information will be within the ATM backbone network 16 along the primary shortest segment P1 of the ring structure with a small network delay. Under abnormal conditions, the same traffic can use a secondary longer path S1 on the ring that provides sufficient delay to require echo cancellation. Because the ATM backbone network 16 operates independently, the transmission delay is unpredictable. For this reason, all traffic for echo cancellation is processed.

After the treatment of the narrowband voice traffic by the echo canceler and the voice enhancement unit 58 out 2 may narrowband voice traffic through a compression unit 60 be compressed. The compression unit 60 compresses the T1 / E1 signals are less than the sum of the input / output service capacity actually over the ATM backbone network 16 is transmitted. Compression can be achieved by using a standard compression protocol such as Adaptive Delta Pulse Code Modulation (ADPCM) or by using custom adaptive protocols that can significantly reduce network capacity requirements.

After the voice traffic from the compression unit 60 is compressed, the T1 / E1 signals are passed through an ATN adaptation level unit 62 adapted to asynchronous transfer mode cells. The control register unit 63 Allows monitoring and provides information on the operation of the T1 / E1 network adapter 50 ,

Asynchronous transfer mode cells are used by the SONET formatter 52 formatted. The SONET formatting unit 52 receives asynchronous transfer mode cells from the T1 / E1 network adapter 50 at a shelf input / output unit 64 , The shelf input / output unit 64 transmits asynchronous transfer mode cells to an ATM convergence unit 66 by a control processor 68 is monitored. The control processor 68 can also send asynchronous transfer mode cells to the ATM convergence unit 66 send for transmission of administrative and management information.

The ATM convergence unit 66 formats asynchronous transfer mode cells from the shelf input / output unit 64 , from an external ATM device via an ATM input / output unit 74 and / or a control processor 68 to a synchronous electrical network signal. The synchronous electrical network signal is from an electrics / optics converter 70 converted into an optical format. The electrics / optics converter 70 sends synchronous optical network signals to an ATM backbone broadband network 16 ,

The SONET formatting unit 52 can be a communication unit 72 for downloading operating system software to the control processor 68 and provide access for external maintenance communication. The SONET formatting unit 52 also includes the ATM input / output unit 74 which involves directly receiving and sending ATM cells from and to the formatter 52 connected external ATM device allows.

In the outbound direction, the SONET formatter receives 52 synchronous optical network signals transporting traffic from the ATM backbone network to asynchronous transfer mode cells. The synchronous optical network signals are from the electrics / optics converter 70 converted into electrical signals. The ATM convergence unit 66 extracts ATM cells from the synchronous electrical signals as monitored by the control processor 68 , The ATM cells are temporarily stored to the shelf input / output unit 64 forwarded.

The T1 / E1 network adapter 50 receives ATM cells from the shelf input / output unit 64 the SONET formatting unit 52 , The ATM cells are handled by the ATM Adaptation Layer unit 62 converted into T1 / E1 signals. The T1 / E1 signals are from the compression unit 60 decompressed. After decompression, the T1 / E1 signals are received from the echo canceler and the speech enhancement unit 58 processed.

After treatment by the echo canceler and speech enhancement unit 58 are the T1 / E1 signals from the transceiver 56 provided with frame and a new Timung. Transducer within the T1 / E1 interface unit 54 prepare frame and timing T1 / E1 signals to transmit narrowband voice traffic to the local access network.

The use of ATM cells as generated by the speech adaptation device 18 for the interface with the ATM backbone broadband network 16 Allows recovery of network transfers in the event of outages or disruptions within the backbone network. Back to 3 , primary and secondary forwarding paths P1 and S1 are available for transporting voice traffic between the end users. The selected forwarding path is determined by the information within the virtual path identifier (VPI) field of each ATM cell. The speech adaptation device 18 For example, the VPI field may change in generating ATM cells in response to an indication that the primary path P1 is unavailable or can not transmit the ATM cells. Provision is also made for redundant main and protection equipment connections M1 and M2 to and from the ATM backbone network 16 which enable the transfer of ATM cells in case of network failures. This ensures a continuous and efficient traffic flow between users or networks running on the ATM backbone broadband network 16 access.

4 Figure 10 is a block diagram of an alternative embodiment of the T1 / E1 network adapter 50 , The T1 / E1 network adapter 50 can provide an adaptation for signals at the DS0 level. The ATM adaptation layer comprises a channel multiplexer 80 , the individual DS0 voice channels via a shared memory 83 to appropriate channel processors 82 distributed. The channel processors 82 perform buffering, conversion, and timing operations on DS0 signals to create ATM cells. A cell distribution unit 84 takes those from the individual channel processors 82 generated ATM cells and organizes the ATM cells for transmission to the SONET formatting unit 52 , The configuration of 4 allows the individual treatment of DS0 channels within DS1 lines (TS / E1).

5 shows a block diagram of various uses of the speech adaptation device 18 within a telecommunications network 100 , The telecommunications network 100 includes a first cross-connect network carrier 110 with a backbone ATM broadband network 16a and a speech adaptation device 18a , The telecommunications network 100 also includes a second cross-connect network carrier 120 with a backbone ATM broadband network 16a and a speech adaptation device 18b , The telecommunications network 100 also includes a local area network 130 with local network carriers 140 using a backbone ATM broadband network 16c are coupled. Each local network carrier comprises a voice adaptation device 18c as an interface to the backbone ATM broadband network 16c , The local area network 130 also includes a tandem circuit having a plurality of speech adaptation devices 18d as an interface to the backbone ATM broadband network 16c with different cross-connection network carriers 110 and 120 , The local area network 130 can with a connecting cable 150 that has an ATM hub 160 , a speech adaptation device 18e and an STM switch 170 includes, communicate.

In contrast to the stand-alone device already shown, the telecommunications network comprises 100 also a private network 150 with ATM hubs 160 and STM switches 170 that with a local area network 130 and a cross-connection network carrier 110 are coupled. As in 5 shown, the speech adaptation device 18 be used in different application scenarios. The integration of the speech adaptation device 18 can be done on a network side of a voice service switching system to provide a SONET / ATM high speed interface. Integration may also be on the access side of a cross-connect system to provide a broadband service connection to the broadband backbone network. The speech adaptation device 18 can also be integrated into customer-located equipment (CLE) to complete the DS1 voice traffic (T1 (E1).) Such CLE integration can be particularly useful when leased lines from private branch exchanges (PBX) for transmission on one Another application for the voice adaptation device is a public or private broadband wide area network 18 is their use as an ATM switch server to perform voice handling functions when required within a broadband network for voice and multimedia traffic from local ATM switches without echo canceling or voice enhancement functions. Another application of the ATM switch server application is to perform a voice protocol conversion so that two non-compliant terminals (eg, a telephone and a multimedia workstation) can exchange intelligent voice traffic. An example of this condition would be for a user of a Plain Old Telephone System (POTS) to attend a conference call between two multimedia terminals using a different language encoding than the u-law PCM format.

Everything In general, a voice adaptation device provides the interface between local narrowband access networks and a backbone broadband network with asynchronous transfer mode. The speech adaptation device converts the signals carried over T1 / E1 signals Narrowband voice traffic into synchronous optical network signals with an asynchronous transfer mode cell format. The speech adaptation device leads one Echo cancellation, Voice enhancement and compression of T1 / E1 signals by, to provide advanced narrowband voice services.

It It is thus clear that a device is provided herewith, the narrowband voice traffic for a local access network adapts to transfer over To enable broadband network with asynchronous transfer mode and thus offers the advantages described above. Even if the preferred embodiment in detail should be clear that different changes, Replacements and adjustments can be made. The speech adaptation device For example, some or all of the services described above may be used provide. Further examples will be clear to the person skilled in the art. without departing from the scope of the invention according to the following claims.

1

• ATM voice adaptation device with echo canceler and voice enhancement, ATM network processing tion and ATM multiplexing

• High-speed connections with echo-treated, line-emulsified virtual paths

12

LEC

14

IXC Echo Path Transit switch T1 / E1

16

ATM Transit switch Echo Path IXC LEC

• ATM-managed backbone network (SONET / SDH facilities for transporting ATM / VP traffic)

3

• Physical diversity
• VP-forwarding

• Local STM access network
• guard
• main facility
• VPI (S1)
• ATM backbone network
• VPI (P1)

• secondary route
• primary route

• ATM backbone switch
• Voice switching exchange with ATM voice adaptation

2

• T1 / E1 network adapter
• Control register with path quality analysis
• test connections
• T1 / E1 interface (transfers)
• Transceiver T1 framing and timing
• EC / VE (DSP)
• compression
• EEL

• T1 / E1 network adapter
• cell pathway
• control bus

• communication
• OS CRAFT I / O
• control processor
• Tax. Vert.
• Shelf I / O
• ATM cells
• Shelf I / O
• ATM Conv. and SONET formatting
• ATM I / O
• ATM management cells
• SOH-function control
• I / O
• External ATM device
• DS3 / STS 1
• T1 / E1 network adapter
• Control register with path quality analysis
• test connections
• T1 / E1 interface (transfers)
• Transceiver T1 framing and timing
• EC / VE (DSP)
• CH-MUX
• Cell Vert.

• Shared memory
• AAL CH-1
• (Buffering, processing and timing)
• cell pathway
• control bus

• communication
• OS CRAFT I / O
• control processor
• Tax. Vert.
• Shelf I / O
• ATM cells
• Shelf I / O
• ATM Conv. and SONET formatting
• ATM I / O
• ATM management cells
• SOH-function control
• I / O

• External ATM device
• DS3 / STS 1

5

• IXC
• IXC # 1
• AVAN
• ATM backbone

• IXC # 2
• AVAN
• ATM backbone

• CAP or Priv. network

• LEC
• AVAN
• Access Tandem
• AVAN

• LEC
• ATM
• LATA
• Backbone network

• AVAN
• LEC # 5
• AVAN
• AVAN
• LEC # 5
• AVAN
• LEC # 5

• Network Management

• ATM hub
• AVAN
• STM PBX
• ATM hub
• AVAN
• STM

• ATM hub / ring
• AVAN
• STM

Claims (12)

Speech adaptation device ( 18 ) for adapting the narrowband voice traffic of a local access network ( 12 . 14 ) to transmit over a broadband network with asynchronous transfer mode ( 16 ), said device comprising: a signal interface circuit ( 54 ) operable to receive narrowband voice traffic from the local access network and to send narrowband voice traffic to the local access network; a transceiver circuit ( 56 ) operable to provide narrowband voice traffic with framing and timing conversion functions; a cell adapter circuit ( 62 ) which is operable to convert the narrowband voice traffic to and from the cells in asynchronous transfer mode; and a formatting unit ( 52 ) operable to convert asynchronous optical network signals transporting these asynchronous transfer mode cells to and from the asynchronous data transfer mode broadband network, characterized in that it comprises: an echo cancellation unit (10); 58 ) operable to eliminate voiceband echo effects from the narrowband voice traffic regardless of the transmission path over the broadband network with asynchronous data transfer mode; and a compression unit ( 60 ) which can be operated to compress and decompress narrowband voice traffic to reduce the signal capacity transmitted over the broadband asynchronous data transfer mode network. Apparatus according to claim 1, further comprising: a speech enhancement unit ( 58 ) which can be operated to improve a signal quality of the narrowband voice traffic. Device according to claim 1, wherein this compression unit can be operated so that an ADPCM compression with the narrowband voice traffic. Device according to claim 1, these asynchronous transfer mode cells being represented by virtual path identifiers over the Broadband network transmitted with asynchronous data transfer mode and this formatting unit can be operated in such a way that they are these virtual path identifiers of asynchronous transfer mode cells Adjusts in response to errors and bottlenecks within the broadband network with asynchronous data transfer mode. Device according to claim 1, wherein this cell adapter circuit can be operated so that it separates the narrowband voice traffic into individual voice channels, to carry out an individual treatment of the individual language channels. Apparatus according to claim 5, wherein said cell adapter circuit comprises: a channel multiplexer ( 80 ) which can be operated to separate and connect individual voice channels; a variety of channel processors ( 82 ) which are operable to convert each individual voice channel into and out of the asynchronous transfer mode cell format; a variety of channel processors ( 82 ) that can be operated to convert each individual digital voice protocol from one digital voice protocol to another digital voice protocol; and a cell distribution unit ( 84 ) which can be operated to transmit asynchronous transfer mode cells to and from this plurality of channel processors. Telecommunications network 10 comprising: a backbone broadband network with asynchronous data transfer mode ( 16 ); a local narrowband access network with synchro a data transfer mode ( 12 . 14 ); and a device according to the preceding claims Telecommunications network according to claim 7, wherein said device is a speech adaptation device ( 18 ) which can be operated as an interface of voice traffic between this backbone broadband network with asynchronous data transfer mode and this local narrowband access network with synchronous data transfer mode, which voice adaptation device can be operated to perform echo cancellation and voice enhancement with this voice traffic independently from the transmission path of the voice traffic over the backbone broadband network with asynchronous data transfer mode, and wherein said voice adaptation device is operable to convert the narrowband voice traffic of said local narrowband access network with synchronous data transfer mode into synchronous optical network signals transporting asynchronous transfer cell format voice traffic for transmission over this backbone broadband network with asynchronous data transfer mode, this backbone broadband network with asynchronous data transfer can be operated so that it transmits these synchronous optical network signals through a ring structure with a primary path and a secondary path, this voice adaptation device can be operated so that it adapts a field for a virtual path identifier, which determines which of these primary or secondary paths is selected in response to error hints and bottlenecks detected by this ring structure and / or the virtual path quality analysis software in processing this speech adaptation device. Telecommunications network according to claim 7, wherein said speech adaptation device with this backbone broadband network with asynchronous data transfer mode or this local narrowband access network with synchronous data transfer mode is integrated. Method as interface of voice traffic between a narrowband network with synchronous data transfer mode ( 12 . 14 ) and a broadband network with asynchronous data transfer mode ( 16 ), said method comprising the steps of: receiving voice traffic from the narrow band network with synchronous transfer mode; Performing framing and timing functions on the voice traffic to place the voice traffic in a wideband timing mode; Converting the voice traffic to an asynchronous transfer mode cell format; and formatting the synchronous transfer mode cells into synchronous optical network signals for transmission over the broadband network with asynchronous data transfer mode, the method being characterized by the steps of: eliminating voiceband echo effects from the voice traffic independent of a transmission path through the asynchronous data transfer mode broadband network; and compressing the voice traffic to reduce the signal capacity over the broadband network with asynchronous data transfer mode. Method according to claim 10, further comprising the step of: Improve the signal quality of voice traffic. Method according to claim 10, further comprising the step of: Receive synchronous optical network signals from the broadband network with asynchronous Transfer Mode; Extracting ATM cells (Asynchronous Transfer Mode) from the synchronous electrical network signals; Convert of asynchronous network signals in voice traffic with synchronous Tansfermodus; Carry out framing and timing functions with voice traffic for placing voice traffic in a narrowband timing mode; and Sending voice data traffic over the narrowband network with synchronous data transfer mode.